Birds, method for producing birds, and bird eggs

Abstract

According to this invention, a bird lays an egg that does not contain an artificially introduced foreign gene in genome thereof and has an ovomucoid content lower than that in a wild type thereof. A method for producing a bird includes a modification step of cleaving the ovomucoid gene locus in a pluripotent stem cell of a bird with programmable endonuclease so as to modify the ovomucoid gene locus and a transplantation step of transplanting the pluripotent stem cell in which the ovomucoid gene locus is modified into an embryo of a bird. A bird egg does not contain an artificially introduced foreign gene in genome thereof and has an ovomucoid content lower than that in a wild type thereof.

1 . A bird that lays an egg that does not contain an artificially introduced foreign gene in genome thereof and has an ovomucoid content lower than that in a wild type thereof. 
     
     
         2 . The bird according to  claim 1 , which includes a termination codon in at least one of first to third exons from a 5′ end of an ovomucoid gene locus, or which does not include an initiation codon in a first exon from a 5′ end of an ovomucoid gene locus. 
     
     
         3 . The bird according to  claim 1 , wherein a signal sequence within the ovomucoid gene locus is modified. 
     
     
         4 . The bird according to  claim 1 , which is a chicken. 
     
     
         5 . A method for producing a bird, which comprises:
 a modification step of cleaving an ovomucoid gene locus of a pluripotent stem cell of a bird with a programmable endonuclease, thereby modifying the ovomucoid gene locus; and   a transplantation step of transplanting the pluripotent stem cell containing the modified ovomucoid gene locus into an embryo of a bird.   
     
     
         6 . The method for producing a bird according to  claim 5 , wherein the programmable endonuclease is transcription activator-like effector nuclease. 
     
     
         7 . The method for producing a bird according to  claim 6 , wherein the transcription activator-like effector nuclease comprises a first nuclease and a second nuclease, the first nuclease comprises an amino acid sequence set forth in SEQ ID NO: 4, and the second nuclease comprises an amino acid sequence set forth in SEQ ID NO: 5. 
     
     
         8 . The method for producing a bird according to  claim 6 , wherein the transcription activator-like effector nuclease comprises a third nuclease and a fourth nuclease, the third nuclease comprises an amino acid sequence set forth in SEQ ID NO: 6, and the fourth nuclease comprises an amino acid sequence set forth in SEQ ID NO: 7. 
     
     
         9 . The method for producing a bird according to  claim 5 , wherein the programmable endonuclease is Cas9 nuclease in a Clustered Regularly Interspaced Short Palindromic Repeat-CRISPR associated protein system. 
     
     
         10 . The method for producing a bird according to  claim 9 , wherein the Cas9 nuclease cleaves double-strand DNA in a region comprising a base sequence set forth in SEQ ID NO: 8 of the ovomucoid gene locus. 
     
     
         11 . The method for producing a bird according to  claim 9 , wherein the Cas9 nuclease cleaves double-strand DNA in a region comprising a base sequence set forth in SEQ ID NO: 9 of the ovomucoid gene locus. 
     
     
         12 . The method for producing a bird according to  claim 9 , wherein the Cas9 nuclease cleaves double-strand DNA in a region comprising a base sequence set forth in SEQ ID NO: 10 of the ovomucoid gene locus. 
     
     
         13 . The method for producing a bird according to  claim 9 , wherein the Cas9 nuclease cleaves double-strand DNA in a region comprising a base sequence set forth in SEQ ID NO: 11 of the ovomucoid gene locus. 
     
     
         14 . The method for producing a bird according to  claim 9 , wherein the Cas9 nuclease cleaves double-strand DNA in a region comprising a base sequence set forth in SEQ ID NO: 12 of the ovomucoid gene locus. 
     
     
         15 . The method for producing a bird according to  claim 9 , wherein the Cas9 nuclease cleaves double-strand DNA in a region comprising base sequence set forth in SEQ ID NO: 13 of the ovomucoid gene locus. 
     
     
         16 . The method for producing a bird according to  claim 1 , wherein an ovomucoid gene locus of an epiblast-derived pluripotent stem cell is modified in the modification step. 
     
     
         17 . A bird egg that does not contain an artificially introduced foreign gene in genome thereof, and that has an ovomucoid content lower than that in a wild type thereof.